/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */
package wx.xml.xalan.xalan.trace;

import android.view.textclassifier.SelectionEvent;

import org.w3c.dom.Node;

import java.lang.reflect.Method;
import java.util.TooManyListenersException;
import java.util.Vector;

import wx.xml.xalan.xalan.templates.ElemTemplateElement;
import wx.xml.xalan.xalan.transformer.TransformerImpl;
import wx.xml.xalan.xpath.XPath;
import wx.xml.xalan.xpath.objects.XObject;

/**
 * This class manages trace listeners, and acts as an
 * interface for the tracing functionality in Xalan.
 */
public class TraceManager {

    /**
     * A transformer instance
     */
    private TransformerImpl m_transformer;
    /**
     * List of listeners who are interested in tracing what's
     * being generated.
     */
    private Vector m_traceListeners = null;

    /**
     * Constructor for the trace manager.
     *
     * @param transformer a non-null instance of a transformer
     */
    public TraceManager(TransformerImpl transformer) {
        m_transformer = transformer;
    }

    /**
     * Add a trace listener for the purposes of debugging and diagnosis.
     *
     * @param tl Trace listener to be added.
     * @throws TooManyListenersException
     */
    public void addTraceListener(TraceListener tl)
        throws TooManyListenersException {

        m_transformer.setDebug(true);

        if (null == m_traceListeners)
            m_traceListeners = new Vector();

        m_traceListeners.addElement(tl);
    }

    /**
     * Remove a trace listener.
     *
     * @param tl Trace listener to be removed.
     */
    public void removeTraceListener(TraceListener tl) {

        if (null != m_traceListeners) {
            m_traceListeners.removeElement(tl);

            // The following line added to fix the bug#5140: hasTraceListeners() returns true
            // after adding and removing a listener.
            // Check: if m_traceListeners is empty, then set it to NULL.
            if (0 == m_traceListeners.size())
                m_traceListeners = null;
        }
    }

    /**
     * Fire a generate event.
     *
     * @param te Generate Event to fire
     */
    public void fireGenerateEvent(GenerateEvent te) {

        if (null != m_traceListeners) {
            int nListeners = m_traceListeners.size();

            for (int i = 0; i < nListeners; i++) {
                TraceListener tl = (TraceListener) m_traceListeners.elementAt(i);

                tl.generated(te);
            }
        }
    }

    /**
     * Tell if trace listeners are present.
     *
     * @return True if there are trace listeners
     */
    public boolean hasTraceListeners() {
        return (null != m_traceListeners);
    }

    /**
     * Fire a trace event.
     *
     * @param styleNode Stylesheet template node
     */
    public void fireTraceEvent(ElemTemplateElement styleNode) {

        if (hasTraceListeners()) {
            int  sourceNode = m_transformer.getXPathContext().getCurrentNode();
            Node source     = getDOMNodeFromDTM(sourceNode);

            fireTraceEvent(new TracerEvent(m_transformer, source,
                m_transformer.getMode(),  /*sourceNode, mode,*/
                styleNode));
        }
    }

    /**
     * Fire a end trace event, after all children of an element have been
     * executed.
     *
     * @param styleNode Stylesheet template node
     */
    public void fireTraceEndEvent(ElemTemplateElement styleNode) {

        if (hasTraceListeners()) {
            int  sourceNode = m_transformer.getXPathContext().getCurrentNode();
            Node source     = getDOMNodeFromDTM(sourceNode);

            fireTraceEndEvent(new TracerEvent(m_transformer, source,
                m_transformer.getMode(),  /*sourceNode, mode,*/
                styleNode));
        }
    }

    /**
     * Fire a trace event.
     *
     * @param te Trace event to fire
     */
    public void fireTraceEndEvent(TracerEvent te) {

        if (hasTraceListeners()) {
            int nListeners = m_traceListeners.size();

            for (int i = 0; i < nListeners; i++) {
                TraceListener tl = (TraceListener) m_traceListeners.elementAt(i);
                if (tl instanceof TraceListenerEx2) {
                    ((TraceListenerEx2) tl).traceEnd(te);
                }
            }
        }
    }


    /**
     * Fire a trace event.
     *
     * @param te Trace event to fire
     */
    public void fireTraceEvent(TracerEvent te) {

        if (hasTraceListeners()) {
            int nListeners = m_traceListeners.size();

            for (int i = 0; i < nListeners; i++) {
                TraceListener tl = (TraceListener) m_traceListeners.elementAt(i);

                tl.trace(te);
            }
        }
    }

    /**
     * Fire a selection event.
     *
     * @param sourceNode    Current source node
     * @param styleNode     node in the style tree reference for the event.
     * @param attributeName The attribute name from which the selection is made.
     * @param xpath         The XPath that executed the selection.
     * @param selection     The result of the selection.
     * @throws javax.xml.transform.TransformerException
     */
    public void fireSelectedEvent(
        int sourceNode, ElemTemplateElement styleNode, String attributeName,
        XPath xpath, XObject selection)
        throws javax.xml.transform.TransformerException {

        if (hasTraceListeners()) {
            Node source = getDOMNodeFromDTM(sourceNode);

            fireSelectedEvent(new SelectionEvent(m_transformer, source, styleNode,
                attributeName, xpath, selection));
        }
    }

    /**
     * Fire a selection event.
     *
     * @param sourceNode    Current source node
     * @param styleNode     node in the style tree reference for the event.
     * @param attributeName The attribute name from which the selection is made.
     * @param xpath         The XPath that executed the selection.
     * @param selection     The result of the selection.
     * @throws javax.xml.transform.TransformerException
     */
    public void fireSelectedEndEvent(
        int sourceNode, ElemTemplateElement styleNode, String attributeName,
        XPath xpath, XObject selection)
        throws javax.xml.transform.TransformerException {

        if (hasTraceListeners()) {
            Node source = getDOMNodeFromDTM(sourceNode);

            fireSelectedEndEvent(new EndSelectionEvent(m_transformer, source, styleNode,
                attributeName, xpath, selection));
        }
    }

    /**
     * Fire a selection event.
     *
     * @param se Selection event to fire
     * @throws javax.xml.transform.TransformerException
     */
    public void fireSelectedEndEvent(EndSelectionEvent se)
        throws javax.xml.transform.TransformerException {

        if (hasTraceListeners()) {
            int nListeners = m_traceListeners.size();

            for (int i = 0; i < nListeners; i++) {
                TraceListener tl = (TraceListener) m_traceListeners.elementAt(i);

                if (tl instanceof TraceListenerEx)
                    ((TraceListenerEx) tl).selectEnd(se);
            }
        }
    }

    /**
     * Fire a selection event.
     *
     * @param se Selection event to fire
     * @throws javax.xml.transform.TransformerException
     */
    public void fireSelectedEvent(SelectionEvent se)
        throws javax.xml.transform.TransformerException {

        if (hasTraceListeners()) {
            int nListeners = m_traceListeners.size();

            for (int i = 0; i < nListeners; i++) {
                TraceListener tl = (TraceListener) m_traceListeners.elementAt(i);

                tl.selected(se);
            }
        }
    }


    /**
     * Fire an end extension event.
     *
     * @param method    The java method about to be executed
     * @param instance  The instance the method will be executed on
     * @param arguments Parameters passed to the method.
     * @see java.lang.reflect.Method#invoke
     */
    public void fireExtensionEndEvent(Method method, Object instance, Object[] arguments) {
        ExtensionEvent ee = new ExtensionEvent(m_transformer, method, instance, arguments);

        if (hasTraceListeners()) {
            int nListeners = m_traceListeners.size();

            for (int i = 0; i < nListeners; i++) {
                TraceListener tl = (TraceListener) m_traceListeners.elementAt(i);
                if (tl instanceof TraceListenerEx3) {
                    ((TraceListenerEx3) tl).extensionEnd(ee);
                }
            }
        }
    }

    /**
     * Fire an end extension event.
     *
     * @param method    The java method about to be executed
     * @param instance  The instance the method will be executed on
     * @param arguments Parameters passed to the method.
     * @see java.lang.reflect.Method#invoke
     */
    public void fireExtensionEvent(Method method, Object instance, Object[] arguments) {
        ExtensionEvent ee = new ExtensionEvent(m_transformer, method, instance, arguments);

        if (hasTraceListeners()) {
            int nListeners = m_traceListeners.size();

            for (int i = 0; i < nListeners; i++) {
                TraceListener tl = (TraceListener) m_traceListeners.elementAt(i);
                if (tl instanceof TraceListenerEx3) {
                    ((TraceListenerEx3) tl).extension(ee);
                }
            }
        }
    }

    /**
     * Fire an end extension event.
     *
     * @param ee the ExtensionEvent to fire
     * @see java.lang.reflect.Method#invoke
     */
    public void fireExtensionEndEvent(ExtensionEvent ee) {
        if (hasTraceListeners()) {
            int nListeners = m_traceListeners.size();

            for (int i = 0; i < nListeners; i++) {
                TraceListener tl = (TraceListener) m_traceListeners.elementAt(i);
                if (tl instanceof TraceListenerEx3) {
                    ((TraceListenerEx3) tl).extensionEnd(ee);
                }
            }
        }
    }

    /**
     * Fire an end extension event.
     *
     * @param ee the ExtensionEvent to fire
     * @see java.lang.reflect.Method#invoke
     */
    public void fireExtensionEvent(ExtensionEvent ee) {

        if (hasTraceListeners()) {
            int nListeners = m_traceListeners.size();

            for (int i = 0; i < nListeners; i++) {
                TraceListener tl = (TraceListener) m_traceListeners.elementAt(i);
                if (tl instanceof TraceListenerEx3) {
                    ((TraceListenerEx3) tl).extension(ee);
                }
            }
        }
    }

    /**
     * Get the DOM Node of the current XPath context, which is possibly null.
     *
     * @param sourceNode the handle on the node used by a DTM.
     */
    private Node getDOMNodeFromDTM(int sourceNode) {
        wx.xml.xalan.xml.dtm.DTM dtm    = m_transformer.getXPathContext().getDTM(sourceNode);
        final Node               source = (dtm == null) ? null : dtm.getNode(sourceNode);
        return source;
    }
}
